Graphene is a two-dimensional hexagonal network of sp2 hybridized carbon atoms. Graphene has been the subject of intense research recently because of its outstanding electrical properties and because of several intriguing phenomena that have been observed in the two-dimensional carbon-based material. For many applications, a suitable method for creating spatially defined patterns of appropriate size (ranging from millimeter to nanometer scales) and shape in graphene is necessary or desirable. For example, graphene can be transformed into a semiconductor over large-areas by patterning it on the nanometer scale into nanoribbons, quantum dots or continuous nanoperforated sheets (“antidot lattices”). Typically, this is accomplished by growing or isolating a full graphene sheet and then etching away the unwanted regions of the graphene from the top-down using lithography in conjunction with reactive ion etching or through ion bombardment.
Unfortunately, top-down patterning creates graphene with atomically-disordered edges, in the form of dangling bonds, defects, chemical functionalization, and roughness. This edge disorder can degrade graphene's electronic, optical, thermal and structural properties, including its electron mobility and strength.
It has been reported that defective and disordered edges of graphene will undergo reorganization at 1500-2000° C. via Joule heating. (Jia et al., Science 2009, 323, 5922, 1701-1705.) However, the high temperatures used during this process are too extreme for many electronics applications.